Moreover, the abundance of chemical compounds and their importance in daily life hindered the chemist from investigating the question, in what does the individuality of the atoms of different elements consist.

The most common and most important result of them is that the nature and size of the effect on corresponding series of different elements are largely an expression of the peculiarity of their atomic structure - or, at least, of the structure of the surface.

By recognizing that the chemical atom is composed of single separable electric quanta, humanity has taken a great step forward in the investigation of the natural world.

An external electric field, meeting it and passing through it, affects the negative as much as the positive quanta of the atom, and pushes the former to one side, and the latter in the other direction.

Many scientists will have to contribute to the solution of the great problem; they will have to follow up and measure all those phenomena in which the atomic structure is directly expressed.

The question of the composition of perceptible objects is one which already occupied the mind of the ancient Greeks.

The emitters of the spectral series are without exception single atoms, not compounds of atoms.